Headlight



iw. G. woon.

v v HEAD'LIGHTS. APPLICATION HLEUAUG, 191e. mzmawfn sm. 25. 19 2o.

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HEADLIGHT.

APPLICATION FILED AUG.5, i918, RENEWED SEPT.25, 1920. l

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W. G. WOOD.

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WILLIAIVI Gr.l VQD, OF BERKELEY, CALIFORNIA, ASSIGNOR TO BERKIEJI..EY LIGHT CORPORATIOLE., 0F SAN FRANCISCO, CALIFORNIA, A CORPORATION 0F NEVADA.

HEADLIGHT.

Specification of Letters Patent.

Patented Jana.` it), 1922.

Application led August 5, 1918, Serial No. 248,303. Renewed September 25, 1920. Serial No. 412,832.

To all iff/1.0m Ii may conce/n Be it known that l. ViLLIAM G. TVOOD, a citizen of the VUnited States, residing at Berkeley, in the county of Alameda and State of California, have invented new and useful Improvements in Headlights, of which the following is a specification.

This invention relates to headlights and more particularly to headlights adapted for automobiles and the like.

The object ofl the present invention is to provide means for projecting a cone-shaped beam and to provide a window or transparent opening which is circular in shape and considerably reduced in area, thereby eliminating all objectionable glare or blinding effect, as the vertical height of the beam is also in this instance limited. In this lamp, viewed from points ahwfc a horizont-al plane of the elevation of tha lamp, neither the source of light, nor the apparent source are in evidence, therefore` there can be absolutely no glare.

Another object of the invention is to provide a novel`form of project-ing reflector and a support for the same. together with means for adjusting' the vertical angular position of the headlights with relation to the forksin which they are mounted.

Another object of the invention is to provide means for converging or dlverging` the light beam as it passes through the. transparent aperture to increase or decrease the area lighted, and to produce a more uniform field of light, and also to provide means for increasing or decreasing the spread of the beam vertically without affecting the spread of the beam horizontally or vice versa.`

Further objects will hereinafter appear.

The invention "consists ot. the parts and the construction and combination of parts as hereinafter more fully described and; claimed` having reference to the accompanying drawings in which- Figure 1 is a central, vertical, longitudinal section through the lamp.

Fig. 2 is a diagrammatic view, showing how the parabolic curvature of the projectino' reflector is obtained.

Tig. 3 is a plan View of the lamp.

F ig. 4 is a front View of the same. v

-Fig. 5 is a diagrammatic view showing how the placing of the lens may converge or diverge thebeam.

Fig. 6 is a diagrammatic view showing how the spread of the light beam may be increased or decreased vertically.

Fig. 'T is a detail side elevation of thc bracket support 23,

Referring to the drawings in detail, A indicates in general a lamp casing, in this instance, constructed of two sections 2 and 3, which are adapted to be secured together b y means of snap hooks, generally indicated at 4. The casing is substantially egg-shaped, when viewed from a side elevation, but is comparatively long and narrow when viewed from a plan or end view, as shown in Figs. 3 and et.

The casing is provided with a window or transparent opening 5 of exceedingly small area. This window is circular in shape and in actual practice is generally less than half an inch in diameter. The window proper is secured in a mounting- G whiclrmay form a portion of the lower casing, as here shown, and the glass may be vsecured in said mounting or in a screw cap 7.

Snitably securedwithin the lower half ot thc casing, as by flanges 8 and rivets 9, is a retlector supporting cage 10. This cage is substantially cylindrical in shape, it being 'provided with an opening at each end, as at ll and 12, for the reception of a parabolic reflector 13 and a section of a parabolic reflector. such as shown at 14. also provided with a forward opening l5 through which the light rays are projected, as will hereinafter be described. Mounted within the parabolic reflector is an electric .bulb 1G which is preferably adjustable with relation to the axis of the reflector to prevent any portion of the filament from eX- tending beyond the focal center, thus eliminating the projection of converging rays and simultaneously permitting the projection of substantially parallel rays against the projecting reflector' 14. This reflector 14 is a section of a comparatively large parabolic retlector, and, therefore, serves the function of concentrating the parallel rays received from the reflector 13; that is, all the rays projected by the'retlector 14 form a coneshaped beam and cross each other at a common focal point, which, in this instance, is located directly in the transparent aperture 5. The rays again spread, after leaving or passing through the aperture. It can, therefore, be seen that a cone-shaped beam will be Thecage isA projected and that the size of the aperture 5 may be exceedingly small. ln theory a pin hole opening would probablyv be sufficient, but an opening from a quarter to a half inch in diameter' is preferably used as it eliminates careful adjustment of the lreflectors within the casing.

The window employed in the present instance is exceedingly small when compared with my copending application Serial No. 248,802, filed August 5, 1918, and with ordinary headlights employing parabolic reflectors. By this means the objectionable glaring or blinding effects generally produced by ordinary headlights arc entirely eliminated, because neither the.. source of light nor the apparent source of light is in evidence, and also because the vertical projections of the light rays are limited.

By referring to the diagrammatic illustration shown in Fig. 2, it will be seen that the projecting reflector 14 is nothing more nor less than a small section of a comparatively large parabolic reflector, such as shown at 17, the section taken being indicated at 18. The foealpoint of the reflector 17 is indicated at 19- and the section 18 employed depends entirely upon the position of the parabolic' reflector 13. This reflector should always assume a position where its longitudinal axis will run parallel with the longitudinal axis 20 of the reflector 17.' The parallel rays projected by the reflector 13 will thus strike the section shown at 18 and this section will project a cone-shaped beam, the rays of which will cross each other at the focal point 19 of the reflector 17. The lower edge of thereflecting projector 18 does Anot extend below the horizontal line shown at 21d-Q1. Thus no projected rays after leaving the aperture will pass above this horizontall line while the majority of the raysl projected by the cone-shaped beam 22, after they leave the aperture 5, will strike the roadway a suitable distance ahead of the car v and spread laterally and give a wide field of light.

The lamp shown in the present instance is adapted to be supported by forks of the usual construction by means of a pair of lugs 23 which project through the sides of the lamp casing. These lugs are provided with setscrews 24 to permit them to be rigidly secured to the forks, but it is nevertheless possible to tilt the lamp vertically, if desired, as the lugs are carried by or formed integral with grooved bearing disks 25 turnably mounted in the'reflector cage 10. A, pair of set-screws QG, one being arranged on cach side of the lamp casing, pass through slotted arms 26 formed integral with the outer' disks, see Fig. 7, and when tightened up, secures the lamp in any adjusted position desired. 1t can, therefore, be seen that although the projecting reflector 18 will not light field.

iaoaeeo project any Ylight rays abovecthe horizontal line 2121, by tilting the lamp as a whole it is possible to raise or lower the projected beam as desired.

By referring to Figs. 1 and 5 it will be seen that a plano convex lens has been placed in the transparent aperture. This lens has two functions, first, that of converging or diverging the light beam projected, and secondly, that of producing a more uniform By referring to the diagrammatic view shown in Fig. 5 it ,will'be seen that positioning of the lens `behind the focal center 50 of the light beam diverges the beam as shown by lines 51, while placing of the lens ahead of' the focal center converges the beam as shown by the lines 52.

Practical experience has proven that these results are obtained, and also that a more uniform field of light is produced, whether the lens is placed in oneposition or another, or at any intermediate point.

While one type of lens is l fre shown I Wish it understood that anyother lens orcombination of the same, that is, a compound lens or the like, may be employed.

By placing a plano convex lens of the cylinder type ahead of the focal point as shown at 53 in Fig. 6, it can readily be seen that it is possible to decrease the spread of the beam horizontally or vice versa. For instance, it may be desired to limit the vertical spread -of the beam to permit it to be thrown further ahead of the car, while it is simultaneously desirable to mai .itain as wide a spread of the beam as possible to cover the entire width of the roadway'. This can readily be accomplished by employing a plano convex lens o f` the cylinder type such as shown at 54. See Fig. 6. The type of lens shown in Fig. 5 will, of course, `spread or converge the entire beam, while the lens shown in Fig. 6 will spread or converge the beam in one direction only without affecting the spread in the op,

posite direction.

This application is ay continuation in part ol my prior application, Ser. Noi 209,834, filed Jan. 2, 1918, patented Dec. 9,1919, No. 1,324,288. j

Having thus described my'invention, what T claim and desire to secure by, Letters Patent is l. A lamp comprising a casing, having a small lightemitting aperture therein, a source of light in the casing, means for pro` jecting light therefrom in the form of parallel rays,and a projecting parabolic reflector to receive the parallel rays, said projecting reflector being of a shape and character to reflect all parallel incident rays in the form of a coneshaped beam wherein all of the rays of said beam will be' focused at a common point located within the light emitting aperture.

isc

bolic reflector, l casing, -a parabolic reflector surrounding said 2. A lamp comprising a casing having a l small light emitting aperture formedthe're; in, a source of light 'in the casing, a project'- ing 'reflector within the casing in the form of a portion of a paraboloid,vmeans for pro-,f

, ing s'aid light adapted to project a beam of substantially p arallel rays against the proin parallelism.with the longitudinal Vaxis from-which thelirst-named parabolic sec- 'and projected in the -form of a cone-shaped beamthrough the transparent aperture.

jecting reflector, said' rays bemg re-reflected .4. A headlight comprising a casing, a projecting reflectormount'ed with said 'cas'- ing, said reflector being a section of a paraa source of light within the light and adapted toproject a beam of sub-4 stantially parallel rays-against the projecting reflector, lsaid last named parabolic reflector havingl its longitudinal axis mounted tional reflectoris taken, and a small trans .parent aperture lformed in the casingat the focal point of said projectmg reflector to permit the forward projection of a coneshaped. beam from the projecting reflector.

5. A headlight comprising a casing, a

projecting reflector mounted within said casing, said reflector being a section of a parabolic reflector, ausource ofl light within' the i casing, a parabolic reflector surrounding 'said vlight and adapted to project a beam of substantially parallel-,rays against the projectlngreflector, said last V named parabolic reflector having itslongitudinal axis mounted in parallelism with the longitudinal axis from which the rst-named parabolic-sec#` tional reflector is taken, a` small transparent apertureformed in the'casing at the focal point of said projecting reflector to permit the forward projection of a cone-shaped beam from the projecting reflector, the rays of said forwardly projecting beam having a focal point where they cross each otherbefore leaving the casing and said aperture Y. being positioned approximately at said focal ing or focal point of the rays.

point and' having an area slightly larger than a cross section taken through the cross- V 6. A headlight comprising a casing, a re j *flector cage rigidly secured within said cas'- lng,l a parabolic reflector secured inone end of said cage, a sectlon of a parabolic resource of light in the witnesses.

flector secured inthe opposite end of the ',cage, la transparent aperture formed in. the' forwardemd of the lampv casing, an o ening formeel-inthe forward end ofthe reflector: spwportingfc'ag'e and a source of flector'.

7. Azheadlight comprising 'a casing, a

p rojefctiiig` reflector witliin thev casing,` 'said vprojecting reflector being a: section of' a parabolic reflector, a small transparentlaper'- ture formed in the casingadjacent'the focali point of'said projecting reflector, a source of light within the casing hidden with respect tothe transparent aperture, a parabolic reflector surrounding said light adapted to project a beam of substantially parallel n rays against the projecting reflector, said rays being re-rellected by the projecting reflector and projected in the form ofa coneshaped beam through the transparent aper-l -ture,"and means for modifying the spread of the cone-shaped beam as it passes through thetransparent aperture.

8. A headlight comprising va .casing having a smallv light emitting ape rt1n;e,a,singleA bottom l'of the casing, means cooperating'with the source of light vto project a beamth'erefro'm in the form of parallel rays,v means --in the upperportion of the casing ligilfywithinthe first named parabolic :re-

to receive the parallelrays and project them in the vform of a cone- -Y lshaped beam, the ray's ofY which cross within j said aperture, said parts being so arranged that the axis of the cone-shaped beam, after leaving the aperture, will be directed downfwardly with the uppermost divergent raysv thereof' on a substantially horizontal line.

y 9. In a lamp or projector a source of light, means cooperating therewith to project a beam of parallel rays and a reiiectorito receive said parallel rays and project them -out in the form of a cone-shaped'beam, said rei' flector being formed of a section of a parab-l oloigl', having its4 lprincipal axis parallel vwith the incident raysibu't located to one side of the incident bea lO. A lamp comprising a casing having a small light emitting aperture, a single source of light located in said casing out of line with the axis of the light emitting aperture, means cooperating withthe source of light to project a' 'beam of parallel rays, and means within the casing to receive the parallel rays and project them out from the casing in the formof a cone-shaped beam with the apex of the cone lying within the light emitting aperture.

In testimony whereof I have hereunto set` I my hand inv'the presence of two subscribing WILLIAM" G. woon. Witnesses: y 

